Remove tui_gen_win_info

Remove tui_gen_win_info

This merges the tui_gen_win_info base class with tui_win_info;
renaming the resulting class to tui_win_info.

gdb/ChangeLog
2020-07-01  Tom Tromey  <tom@tromey.com>

	* tui/tui-wingeneral.c (tui_win_info::refresh_window): Move from
	tui_gen_win_info.
	(tui_win_info::make_window): Merge with
	tui_gen_win_info::make_window.
	(tui_win_info::make_visible): Move from tui_gen_win_info.
	* tui/tui-win.c (tui_win_info::max_width): Move from
	tui_gen_win_info.
	* tui/tui-layout.h (class tui_layout_window) <m_window>: Change
	type.
	<window_factory>: Likewise.
	* tui/tui-layout.c (tui_win_info::resize): Move from
	tui_gen_win_info.
	(make_standard_window): Change return type.
	(get_locator_window, tui_get_window_by_name): Likewise.
	(tui_layout_window::apply): Remove a cast.
	* tui/tui-data.h (MIN_WIN_HEIGHT): Move earlier.
	(struct tui_win_info): Merge with tui_gen_win_info.
	(struct tui_gen_win_info): Remove.